Fighting climate change with air conditioners

Using technology currently in development, AC units in skyscrapers and even your home could get turned into machines that not only capture CO2, but transform the stuff into a fuel for powering vehicles that are difficult to electrify, like cargo ships. The concept, called crowd oil, is still theoretical and faces many challenges. But in these desperate times, crowd oil might have a place in the fight to curb climate change.

To retrofit an air conditioner to capture CO2 and turn it into fuel, you’d need a rather extensive overhaul of the components. Meaning, you wouldn’t just be able to ship a universal device for folks to bolt onto their units. First of all, you’d need to incorporate a filter that would absorb CO2 and water from the air. You’d also need to include an electrolyzer to strip the oxygen molecule from H2O to get H2, which you’d then combine with CO2 to get hydrocarbon fuels. “Everyone can have their own oil well, basically,” Ozin says.

Theoretically, anywhere you have an air conditioner, you have a way to make synthetic fuel.

For this process to be carbon neutral, though, all those souped-up air conditioners would need to be powered with renewables, because burning the synthetic fuel would also produce emissions. To address that problem, Dittmeyer proposes turning whole buildings into solar panels—placing them not just on rooftops but potentially coating facades and windows with ultrathin, largely transparent panels.

“Carbon-neutral hydrocarbon fuels from electricity can help solve two of our biggest energy challenges: managing intermittent renewables and decarbonizing the hard-to-electrify parts of transportation and industry,” says David Keith, acting chief scientist of Carbon Engineering, which is developing much larger stand-alone devices for sucking CO2 out of the air and storing it, known as carbon capture and storage, or CCS.